JP2965913B2 - Three-dimensional tooth surface modification is helical or helical gear - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a three-dimensional flank-reshaping helical gear and a helical gear which can reduce vibration and noise generated when meshing with a helical gear and a helical gear. More specifically, in a helical / helical gear having a long tooth width for transmitting a high load, a three-dimensional tooth whose vibration and noise are reduced by not changing conceptually the total contact line length at the time of meshing of the teeth. Surface modification is related to helical and helical gears.

[0002]

2. Description of the Related Art Conventionally, vibrations of a gear are generally caused by the fact that the spring stiffness of a meshing tooth group fluctuates as the gear meshes, and that a machining error exists on the tooth surface. It is known to be caused by

[0003] variation of the spring stiffness of the teeth, as shown in the illustration of FIG. 5, the tooth when a load W is applied is elastically deformed from the drive gear G ₁ to the tooth surface of the driven gear G _2, deflection thereof will be only δ min rotation angle of the gear is delayed as the imaginary line, which as shown in the illustration of FIG. 6, the drive gear G ₁ whole imaginary line only parallel to the deflection δ min and direction of the load W It said to have moved to the driven gear G ₂ side as.

Considering the load W in a helical gear, as shown in an explanatory diagram of FIG. 7, the load distribution U gradually increases from the start of meshing, reaches a maximum at a central portion, and then gradually increases. It will work to decrease.

[0005] On the other hand, even if it is assumed that the input load is constant and there is no machining error in the tooth surface, the gear is weak because both ends in the tooth width direction are open at one end and strong at the central portion. The local rigidity of the tooth differs depending on the meshing position of the tooth to which the load is applied, and this difference causes a difference in the local rigidity. The same can be said for the difference in rigidity between the weak tip and the strong root. Therefore, in the drive side helical gear and the helical gear that start meshing from the dedendum side and end meshing on the dedendum side and on the driven side starting meshing from the dedendum side and ending with the dedendum side, the above load distribution Even if the same load is applied to both ends in the tooth width direction, the rigidity changes at the start and end of the engagement.

Assuming that such a change in rigidity is assumed by a spring, as shown in FIG. 6, it is assumed that the power between the driving gear G1 and the driven gear G2 is transmitted by a spring k. The difference in local stiffness depending on the engagement position is shown in FIG.
As shown by the thickness of the spring k, the time progress of the engagement weak both end portions, that said central portion is transmitting power while supporting by different spring k strong spring constant. Supporting Tsu <br/> Te, the spring constant to transmit with the progress of engagement is possible to generate vibration and noise to change.

Further, as shown in the perspective view of FIG. 8, the sum of the simultaneous contact line lengths (hereinafter, referred to as the “total simultaneous contact line length”) changes with the progress of the meshing. In other words, the oblique contact line L is such that the contact line L gradually increases from the start of meshing along the meshing traveling direction V, and the complete contact line Lo
Since the contact line L gradually becomes shorter toward the end of the meshing and the meshing ends, the shared load itself changes with the progress of the meshing due to the change in the length of each contacting line L. The lines L mesh with each other while increasing and decreasing the total length.

A description will be given assuming that such a change in the total length of the contact lines is assumed to be a spring. Although not shown, power is transmitted while the number of springs k constantly fluctuates (increases or decreases) with the progress of meshing. It can be said that there is.

[0009] Thus, the driven gear G ₂ is will be subject to complicated non-uniform rotary and load changes under these effects at the time of power transmission, and to generate vibration and noise.

[0010]

By the way, as shown in the side view of the tooth shown in FIG. 9, the temporal change of the total length of the simultaneous contact line with the progress of the meshing of the helical gear and the helical gear is as follows.
The tooth trace direction S is set to an integer n times the pitch Ps, or the meshing length R in the gear setting direction is set to an integer k times the pitch Pr, that is, either the frontal meshing rate or the overlapping meshing rate is increased. It is generally known that by making it an integer, the concept can be nullified. However, it is impossible to design and manufacture all helical and helical gears having various use conditions at such an integer pitch.

Here, by conventional two-dimensional tooth surface modification (tooth shape modification such as tooth profile modification and end relief or a combination thereof) , the frontal meshing ratio in actual tooth contact is obtained.
Alternatively, it is conceivable to make any one of the overlapping meshing ratios an integer.In this case, the total length of the simultaneous contact lines can be kept unchanged. The local stiffness differs depending on the position on the tooth surface. Further, as shown in the front view of the helical gear in FIG. 10, the weakness of the local stiffness at the incompletely shaped portion 11a of the tooth 11 at the tooth width end cannot be solved. Therefore, as described above, the load distribution on the contact line periodically fluctuates as the meshing progresses. Therefore, the amount of deflection δ of each meshing tooth 11
(Figure 5) varies with the progress of engagement delay be varied vibration and noise of driven gear G ₂ is generated to the drive gear.

Therefore, the front engagement ratio or the overlap engagement ratio
Tooth modification with only one of the integers in mind cannot provide sufficient vibration and noise reduction,
It is necessary to modify the tooth surface in consideration of the effect of the local stiffness of the tooth on the load distribution on the contact line. In addition, it is necessary to consider tooth surface strength such as Hertz stress.

On the other hand, there is always a processing error in the tooth surface, and the meshing point deviates from the theoretically correct involute tooth surface shape, so that the driven gear rotates unequally to generate vibration. In addition, depending on the tooth surface modification shape (processing target shape) as a design instruction which is determined in consideration of the tooth surface strength and the mitigation of the impact at the start of meshing, the tooth contact area (contact area on the tooth surface) and the contact line The load distribution changes, and as a result, the total spring stiffness of the driving / driven gear pair changes, and vibration occurs.

Here, the influence of the machining error on gear vibration can be dealt with by improving accuracy.
A problem in actual low-vibration design of gears is that an optimal design method as a general solution has not been established in determining a tooth surface modification shape determined by tooth surface modification such as tooth profile modification and tooth trace modification. That is, module, number of teeth,
The basic specifications such as tooth width and the shape, range and absolute value of tooth surface modification are not independent of each other, but affect the above-mentioned simultaneous contact line total length and the time change of the load distribution on the contact line in a complicated manner. The effect of each factor in the basic specifications on gear vibration has been qualitatively elucidated, but after the basic specifications were determined, the tooth surface modification design required the entire tooth surface to be modified. An optimal design method for reducing vibration by quantitatively determining the shape, range, and absolute value has not been established.

Therefore, conventionally, they have been determined empirically in consideration of the tooth surface strength or the like, or the tooth profile modification shown in FIG. (b) Tooth muscle modification, (c) Two-dimensional tooth surface modification by combining tooth shape modification and tooth muscle modification, etc.
The repetitive calculation while changing the assumption of the tooth surface modification specification had to be determined by complicated trial and error performed for each basic specification and gear operating condition.

As described above, the tooth surface modification specification is first assumed, the index value of the gear vibrating force is obtained by a simulation program, and the tooth surface modification specification is changed based on the result, and the recalculation is performed. The task of performing a complicated review of errors is a task that requires a lot of time and effort.

Moreover, the employed tooth surface modification specification may not always be an essential optimum design. This is due to the local stiffness change mainly due to the imperfect part of the tooth shape at the end of the tooth width of the helical / helical gear having a finite tooth width and the contact line of the imperfect length part of the simultaneous contact line as well. This is because the change in length always participates in the change in the total spring stiffness as a pair of driving and driven gears, which requires a two-dimensional analysis of tooth shape modification and tooth trace modification in the relevant part. The complexity of making low vibration design difficult.

Therefore, it is necessary to reduce vibration and noise as much as possible. For example, in a helical gear / a helical gear having a long tooth width for transmitting a high load in a submersible research vessel, an ocean observation vessel, a low noise equipment, or the like. There is a strong desire to effectively reduce vibration, noise and noise.

In the case of a small helical gear having a short tooth width, for example, as in the invention described in Japanese Patent Application Laid-Open No. 63-180766, the tooth contact portions of a pair of gears meshing with each other are shifted in the meshing direction. A low-vibration / low-noise gear has been invented by tooth surface modification in which the pressure angle is gradually changed depending on the position of the tooth traces so as to extend long along the tooth trace. However, this invention has a problem in the above-described two-dimensional tooth surface modification design. Of these, it is not possible to fundamentally solve the problem of what modification range and absolute value are optimal in given basic specifications.

[0020]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the invention according to the present application provides a helical / helical gear having a long tooth width for transmitting a high load. A complete contact line area having a width of an integral multiple of the line pitch is left, and no contact occurs when meshing with tooth surfaces other than the complete contact line area.
A dimensional bias tooth surface modification is applied. As a result, the total length of the simultaneous contact lines is conceptually invariant with respect to the progress of meshing, and the load distribution on the contact lines is also substantially unchanged with respect to the progress of meshing, thereby reducing vibration and noise during meshing. .

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention according to this application has a reference flank having an involute curve as a tooth profile, and has a long helical / cylindrical helical gear having a long tooth width for transmitting a high load. A three-dimensional bias tooth surface modification is performed such that a complete contact line region having a width that is an integral multiple of the contact line pitch is left, and contact does not occur at the time of meshing with tooth surfaces other than the complete contact line region. As described above, a three-dimensional bias tooth surface modification is performed so that a complete contact line area having a width of an integral multiple of the tooth width direction contact line pitch is left and no contact occurs when other tooth surfaces are meshed. Up,
Power can always be transmitted by a constant total contact line length only in the complete contact line region.

Further, a continuous curved surface is formed from the meshing start portion of the tooth surface modification region to the complete contact line region, and a continuous curved surface is formed from the complete contact line region to the meshing end portion of the tooth surface modification region. However, if these two curved surfaces are formed by three-dimensional bias tooth surface modification in which the tooth profile differs depending on the position in the tooth trace direction, power can be transmitted by smoothly meshing without generating a large impact at the start and end of meshing. Can be.

Further, by setting the maximum amount of modification in the normal direction of the tooth surface to which the bias tooth surface modification has been performed to be at least substantially the same as the amount of deflection at the time of gear engagement, an impact can be caused even by the deflection of the teeth at the time of engagement. Will not occur.

When the correction in the normal direction of the tooth surface with the bias tooth surface modified is expressed on a working surface as a relative modification amount between a pair of driving and driven gears meshing with each other,
If the contour line is formed in a tooth surface modified shape that is substantially parallel to the inclination of the contact line, the contact line moves in a direction substantially perpendicular to the contour line as the meshing progresses, so that the impact can be reduced.

Furthermore, if the start point of the tooth end side of the contact line at the start of meshing of the complete contact line area and the end point of the tooth end of the contact line at the end of meshing are formed inward from both ends in the tooth width direction, the tooth width is increased. The effect of local rigidity at the end in the direction can be almost eliminated.

When the actual overlapping mesh ratio is set to an integer of at least 2 or more, power can be reliably transmitted by a plurality of teeth without changing the total length of the simultaneous contact line in a helical or helical gear having a long tooth width. it can.

Further, when the front meshing ratio is at least 2 or more, power can be transmitted more reliably.

[0028]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings using a helical gear as an example. Fig. 1 (a)
1 is a perspective view showing the teeth of a helical gear according to a first embodiment of the present application, and (b) is a cross-sectional view taken along the line AA of (a). FIG. 2 is an explanatory diagram showing a three-dimensional tooth surface modification region in which the tooth surface of FIG. 1 is developed in a plane to leave a complete contact line region of the working surface. FIG. 3 similarly shows another three-dimensional tooth surface modification region. FIG. In these drawings, the gears on the driving side are taken as an example, and therefore, the case where the meshing starts from the tooth root side and ends with the tooth tip side is illustrated. In the case of a driven gear, meshing starts at the tooth tip side and ends at the tooth root side.

As shown in the figure, in this embodiment, the tooth 1 of the helical gear having a reference flank having an involute curve as a tooth profile has an integral multiple of the contact line pitch Ps in the tooth trace direction S (3 in this example). Double), and the tooth profile is determined by the position in the tooth trace direction S on a curved surface that continues from the contact line Ls at the start of meshing of the complete contact line region F to the virtual meshing start portion 2 while leaving the complete contact line region F having a width of In addition to performing a three-dimensional bias tooth surface modification of a modification amount T that does not cause meshing contact due to a different shape,
The tooth trace direction S is a continuous curved surface extending from the engagement end contact line Le of the complete contact line region F to the virtual engagement end portion 3.
The three-dimensional bias tooth surface modification of the modification amount T that does not cause meshing contact due to different tooth shapes depending on the position is performed. Therefore, the tooth surface is formed in the tooth surface modification region Es on the meshing start side, the complete contact line region F, and the tooth surface modification region Es on the meshing end side. In this embodiment illustrates the actual overlap meshing ratio 3 full contact line L ₀ is the four integers.

Therefore, on the curved surface from the tooth surface modification region Es of the virtual meshing start portion 2 to the meshing contact line Ls, the meshing starts at the meshing contact line Ls without the meshing contact of the teeth. And the meshing ends at the contact line Le at the end of meshing of the complete contact line region F,
Even in the tooth surface modification region Ee to the virtual meshing end portion 3, the meshing contact of the teeth does not occur and the virtual meshing end portion 3 is formed.
Will be reached.

In this embodiment, the correction amount T in the normal direction of the tooth surface at the virtual meshing start portion 2 and the virtual meshing end portion 3 in this bias correction is, as shown in FIG. It is set so as to be at least the amount of deflection at the time of gear engagement (the above-mentioned δ, for example, about 10 μm), and bias correction is performed on a curved surface that continues from the engagement start portion 2 to the involute curved surface. . If this modification amount T is equal to or more than the amount of deflection at the time of gear engagement, it is possible to avoid the impact at the start of engagement.

In this embodiment, as an example, the modified amount T at the start of meshing and the modified amount T at the end of meshing are the same. Since the amount of deflection is different, if the amount of modification T at the start of meshing is set to be slightly larger than the amount of modification T at the end of meshing, the amount of deflection in the tooth width direction in the progress of meshing of teeth can be made substantially the same. it can.

By connecting the complete contact line region F and the tooth surface modification regions Es and Ee with curved surfaces as described above, the start and end of the engagement of the complete contact line region F can be smoothly advanced. Even if a slight manufacturing error occurs, the meshing can be performed without generating vibration or noise.

The three-dimensional tooth surface modification will be described with reference to the plane of operation of FIG. 2. From the complete contact line region F which becomes a parallelogram due to the inclination α of the contact line, the imaginary meshing start portion 2 is formed. A three-dimensional tooth surface modification region Es, Ee is formed toward the virtual meshing end portion 3 and the virtual meshing end portion 3. It has been modified to remove the quantity T.

According to the helical gear of the first embodiment configured as described above, the three-dimensional tooth surface modification region Es from the virtual meshing start portion 2 to the complete contact line region F comes into complete contact. the 3-dimensional bias modification subjected to the three-dimensional tooth surface modification area Ee from the line region F to the end portion 3 of engagement on the virtual, meshing drive gear G ₁ when the driven gear G ₂ and 3 of In order to transmit power by contacting only in the complete contact line region F without contacting in the three-dimensional tooth surface modification regions Es and Ee, the total length of the simultaneous contact lines is made substantially invariant with the progress of meshing, and the tooth width is changed. The load distribution on the contact line is almost invariant to the progress of the meshing without being affected by the incomplete shape of the teeth at the end. Accordingly, there is almost no change in the load acting on the teeth when meshing with each other, and the meshing teeth 1 for transmitting power always mesh continuously only with the complete contact line region F, and the teeth 1 in the complete contact ship region F In any position, power is transmitted while always receiving a constant load to reduce vibration and noise caused by the elastic deformation of the teeth 1 and the change in the total length of the simultaneous contact line, thereby reducing the vibration and noise of the helical gear. Noise can be realized.

In the first embodiment, the three-dimensional tooth surface modification regions Es and Ee and the complete contact line region F are configured to be continuous with a smooth curve. However, in the second embodiment shown in FIG. As shown in the explanatory view of the other developed working surface, the three-dimensional tooth flank modified areas Es and Ee are completely formed by providing a step at the contact line Ls at the start of engagement with the contact line Ls at the end of the complete contact line area F. Even if it is cut off, it can be configured to engage only in the complete contact line region F, so that even in this case, constant power transmission can always be performed only by the complete contact line region F, Vibration and noise of the helical gear caused by deformation and change in the total length of the simultaneous contact line can be reduced. However, in this example, if there is an alignment error or the like, the engagement starting from the contact line Ls may have an impact. In the second embodiment,
An example is shown in which the three-dimensional tooth flank modified regions Es and Ee are both shaved off by the same modified amount T. Also in this example, similarly to the above-described first embodiment, the virtual correction amount T at the start of meshing may be slightly increased.

By the way, as the tooth surface modification shape (bias relief) of the bias modification in the first embodiment,
As shown in the explanatory view of the working surface in which the reference tooth surface of FIG. 4 is developed, it is expressed on the working surface H as the relative amount of modification in the normal direction of the tooth surface between a pair of driving and driven gears meshing with each other. When
If the contour line m is formed so as to be substantially parallel to the inclination α of the contact line L (FIG. 8), the meshing can be smoothly advanced with the movement of the contact line L due to the meshing of the teeth.
In this way, a three-dimensional tooth surface modification helical gear or a helical gear can be configured in consideration of soft landing for reducing impact at the beginning of meshing due to a high load or an alignment error. In FIG. 4, the same processing is performed on the tooth surface modification area Ee at the end of meshing. However, even if such processing is performed only on the tooth surface modification area Es on the meshing start side, the meshing starts. Works effectively.

Further, as the meshing state of the gears progresses, the contact line is moved in a direction substantially parallel to and perpendicular to the contour line of the correction amount of the normal direction of the tooth surface on the working surface, so that normal meshing is achieved. If the movement is smooth, the vibration and noise at the time of meshing can be reduced as much as possible even if the position at the beginning or end of meshing is slightly shifted.

On the other hand, in the first and second embodiments, the start point Fs on the tip side of the contact line Ls at which the complete contact line region F starts to mesh.
The (tooth end side start point) and the dedendum side end point Fe (tooth end side end point) of the meshing end contact line Le are appropriately formed inside from both ends of the tooth 1. Therefore, when the load is large, the end portion in the tooth width direction may be affected by a change in local rigidity.

Therefore, in such a case, if the tip start side Fs and the root end point Fe are formed at least three times inside the tooth height r from both ends in the tooth width direction, the local point at the tooth end can be obtained. Since the change in the bending of the teeth can be made substantially constant without receiving the change in the rigidity, the power can be transmitted without being affected by the change in the local rigidity at the tooth end.

[0041] In the case of applying the three-dimensional tooth surface modification in the invention according to this application, the actual tooth contact that enables low vibration, that tooth trace direction width per corresponds to an integer of overlapping meshing rate It is important that the actual overlap meshing ratio be an integer of at least 2 or more. In this case, the front meshing ratio is not necessarily required to be an integer, but is desirably 2 or more.

Further, the helical gear and the helical gear according to this application are designed to have a low vibration design by using a three-dimensional tooth surface modification processing method to unitarily analyze the complexity of a conventional two-dimensional analysis at the design stage. In this case, the optimum design can be easily performed, and the effect of the analysis error on the realization thereof can be minimized, so that the actual vibration level can be reduced with higher accuracy.

As described above, according to the invention of this application, the total length of the simultaneous contact line of the helical gear and the helical gear is conceptually invariant with the progress of meshing, and the load distribution on the contact line is also meshed. In order to minimize the time variation of the total spring stiffness of the pair of driving and driven gears, which is almost invariable to the progress of the tooth, the tooth shape is modified three-dimensionally depending on the position in the tooth trace direction. Provide helical gear and helical gear,
One solution in low vibration design of bevel gears can be provided.

As the helical / helical gear having a long tooth width for transmitting a high load on a reference tooth surface having an involute curve as a tooth profile to which the present invention is applied, for example,
It is a helical gear or a helical gear having an overlapping meshing ratio of at least 2 or more. As such a helical gear or a helical gear, for example, in a large-capacity and large-capacity gearbox such as a marine or industrial machine,
In particular, the invention according to this application is effective for helical gears and helical gears that require low vibration and low noise.

In the above embodiment, a helical gear has been described as an example. However, a similar effect can be obtained with a helical gear, and the invention according to this application has a contact line with a tooth surface. Similar functions and effects can be obtained with a tilted gear.

[0046]

The invention according to the present application is configured as described above, and has the following effects.

According to the three-dimensional helical and helical gears according to the first to seventh aspects, the total length of the simultaneous contact line is conceptually invariant with the progress of the meshing, and the load distribution on the contact line. Since the three-dimensional bias tooth surface modification is made substantially invariant to the progress of the meshing, the time variation of the total spring stiffness of the pair of driving and driven gears is reduced. / It is possible to greatly reduce the vibration and noise of the bevel gear.

Further, since the three-dimensional tooth surface modification area is clear, it is free from the complicated examination work of tooth surface modification due to the conventional trial and error. The vibration level can be reduced, and the working time and labor can be significantly reduced.

In particular, according to the second aspect, the smooth meshing proceeds from the three-dimensionally biased tooth surface-modified tooth surface modified region to the involute curved surface of the complete contact line region. Power can be smoothly transmitted without generating vibration or noise at the beginning and end of the engagement.

In particular, according to the third aspect, at least the amount of deformation set to be substantially the same as the amount of deflection at the time of gear engagement,
It is possible to configure a helical gear / a helical gear that does not generate vibration or noise due to impact even when the teeth are bent.

In particular, according to the fourth aspect, since the contour line of the three-dimensional tooth surface modification has a tooth surface modification shape that is substantially parallel to the inclination of the contact line, the meshing start and end in the complete contact line region can be more smoothly performed. The meshing can be performed, and the reduction of vibration and noise can be more reliably achieved.

[0052] In particular, according to claim 5, the tooth root side of the tooth tip side and meshing end line of contact meshing start line of contact completely contact line region across <br/> or al the side of the tooth width direction Because of this, it is possible to form a helical gear or a helical gear that can always transmit power stably with almost no influence of local rigidity at the tooth end.

In particular, according to the sixth aspect, the helical / shear having a long tooth width with the actual overlap meshing ratio being an integer of at least 2 or more.
In a bevel gear, power can be transmitted reliably by a plurality of teeth.

In particular, according to the seventh aspect, in addition to the effect of the sixth aspect, since the front meshing ratio is at least two or more, power can be transmitted more reliably by a plurality of teeth.

[Brief description of the drawings]

FIG. 1 is a drawing of a helical gear tooth showing a first embodiment of the invention according to the present application, (a) is a perspective view, and (b) is a cross-sectional view along AA of (a). .

FIG. 2 is an explanatory view showing a three-dimensional tooth surface modification region in which the tooth surface of FIG. 1 is developed in a plane to leave a complete contact line region of an operation surface.

FIG. 3 is an explanatory diagram showing another three-dimensional tooth surface modification region in which the tooth surface of FIG. 1 is developed in a plane to leave a complete contact line region of the working surface.

FIG. 4 is an explanatory view showing an operation surface obtained by developing a reference tooth surface of the tooth of FIG. 1;

FIG. 5 is an explanatory diagram showing a meshing state of a conventional gear.

FIG. 6 is an explanatory view showing the operation of the gears shown in FIG. 5 in a meshing state.

FIG. 7 is an explanatory diagram showing local rigidity in a conventional helical gear.

FIG. 8 is a perspective view showing a contact line in a conventional helical / helical gear.

FIG. 9 is a side view of a tooth of a conventional helical gear.

FIG. 10 is a side view showing a conventional helical gear.

11A and 11B are drawings showing a conventional tooth surface modification, in which FIG. 11A is a perspective view showing a combination of tooth shape modification, FIG. 11B is a diagram showing tooth muscle modification, and FIG.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Teeth 2 ... Mesh start part 3 ... Mesh end part T ... Modification amount r ... Tooth setting S ... Tooth trace direction L ... Contact line Ls ... Mesh start contact line Le ... Mesh end contact line F ... Complete contact Line area Fs: Start point on the tooth tip side (start point on the tooth end) Fe: End point on the root side (end point on the tooth end) Es: Tooth surface modification area Ee: Tooth surface modification area V: Meshing progress direction R : Toothing direction engagement length H: Working surface m: Contour line Ps: Tooth trace direction pitch Pr: Toothing direction pitch α: Contact line inclination δ: Deflection amount

Continuation of the front page (72) Inventor Mitsuru Obana 3-1-1 Higashikawasaki-cho, Chuo-ku, Kobe-shi, Hyogo Kawasaki Heavy Industries, Ltd. Kobe Plant (56) References JP-A-3-28565 (JP, A) Hei 8-285048 (JP, A) JP-A-9-53702 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) F16H 55/08

Claims (7)

(57) [Claims] 1. A helical or helical gear having a long tooth width for transmitting a high load having a reference tooth surface having an involute curve as a tooth profile, wherein an integer of a contact line pitch in a tooth width direction is provided on a tooth surface of the gear. A three-dimensional tooth flank modification characterized by applying a three-dimensional bias tooth flank modification that leaves a double contact width complete contact line area and does not cause contact at the time of meshing on a tooth surface other than the complete contact line area. Sub gear / Evan gear. 2. A continuous curved surface is formed from the meshing start portion of the tooth surface modification region to the complete contact line region, and a continuous curved surface is formed from the complete contact line region to the meshing end portion of the tooth surface modification region. 3. The helical and / or helical gear according to claim 1, wherein the two curved surfaces are formed by three-dimensional bias tooth surface modification in which the tooth profile varies depending on the position in the tooth trace direction. 3. The method according to claim 1, wherein the maximum modification amount in the normal direction of the tooth surface on which the bias tooth surface modification is performed is set to be at least substantially equal to the amount of deflection at the time of gear engagement. The three-dimensional tooth surface modification is a helical / yamabaya gear. 4. When the correction in the normal direction of the tooth surface subjected to bias tooth surface modification is expressed on a working surface as a relative modification amount between a pair of driving and driven gears meshing with each other, the contour line is The three-dimensional tooth surface modified helical and / or helical gear according to any one of claims 1 to 3, wherein the tooth surface is modified in a tooth surface modified shape substantially parallel to the inclination of the contact line. 5. The method according to claim 5, wherein the start point of the contact line on the tooth end side of the contact line and the end point of the contact line on the tooth end side of the complete contact line region are formed inside from both ends in the tooth width direction. The three-dimensional tooth surface modification helical or helical gear according to any one of claims 1 to 4. 6. The method according to claim 1, wherein the actual overlapping mesh ratio is an integer of at least 2 or more.
The three-dimensional tooth surface modification described in the paragraph is a helical gear / a helical gear. 7. The three-dimensional tooth surface modification helical and / or helical gear according to claim 6, wherein the front meshing ratio is at least two or more.